Long-Acting Injection and Implant Preferences and Trade-Offs for HIV Prevention Among South African Male Youth

Background: Long-acting pre-exposure prophylaxis (LA-PrEP) formulated as implants and injections are promising prevention method strategies offering simplicity, discretion, and long dose duration. Men are important end users of LA-PrEP, and early assessment of their preferences could enhance downstream male engagement in HIV prevention.

Methods: A discrete-choice experiment survey was conducted with 406 men, aged 18-24, in Cape Town, South Africa, to assess preferences for 5 LA-PrEP attributes with 2-4 pictorially-depicted levels: delivery form, duration, insertion location, soreness, and delivery facility. Latent class analysis was used to explore heterogeneity of preferences and estimate preference shares.

Results: The median age was 21 (interquartile range 19-22), and 47% were men who have sex with men. Duration was the most important product attribute. Latent class analysis identified 3 classes: "duration-dominant decision makers" (46%) were the largest class, defined by significant preference for a longer duration product. "Comprehensive decision makers" (36%) had preferences shaped equally by multiple attributes and preferred implants. "Injection-dominant decision makers" (18%) had strong preference for injections (vs. implant) and were significantly more likely to be men who have sex with men. When estimating shares for a 2-month injection in the buttocks with mild soreness (HPTN regimen) vs. a 6-month implant (to arm) with moderate soreness (current target), 95% of "injection-dominant decision makers" would choose injections, whereas 79% and 63% of "duration-dominant decision makers" and "comprehensive decision makers" would choose implant.

Conclusions: Young South African men indicated acceptability for LA-PrEP. Preferences were shaped mainly by duration, suggesting a sizeable market for implants, and underscoring the importance of product choice. Further research into men's acceptability of LA PrEP strategies to achieve engagement in these HIV prevention tools constitutes a priority.